Re: Toast rel options

On Wed, 2010-04-28 at 21:11 -0400, Tom Lane wrote:
> Simon Riggs  writes:
> > It's possible to set toast reloptions for tables that don't have toast
> > tables at all. e.g. 
> 
> > create table test (c1 integer);
> > ALTER TABLE test SET (toast.autovacuum_enabled = off);
> 
> > Why?
> 
> 1.  Why not?
> 
> 2. They might have toast tables later, after an ALTER ADD COLUMN
> for instance.

Main reason is that this doesn't do anything. The toast reloptions are
stored on the toast table, so if it doesn't exist then there are no
reloptions. They aren't saved for later and won't be set of later add a
column which causes a toast table to be added.

> 3. They might have had/needed a toast table in the past.  Do
> we need to make ALTER DROP COLUMN capable of flushing those
> reloptions, so that they won't cause a failure at dump/reload?
> 
> I don't see any advantage whatsoever to forbidding this, and
> a lot of corner cases to take care of if we did try to forbid it.

Not required.

Why do we protect against this?

postgres=# alter table test set (nonexistent = on);
ERROR:  unrecognized parameter "notexistent"

Also, this seems not to work?

postgres=# alter table test set (my.expectation = on);
ERROR:  unrecognized parameter namespace "my"

I thought we had enabled custom table options in this release?
Or was that deferred, or even rejected completely?

-- Simon Riggs           www.2ndQuadrant.com